DISCUSSION OF PERTINENT PRIOR DISCLOSURES
Interconnect sleeves for electrical connection have long been known and used. An example of an electrical interconnect is R. J. T. Clabburn, U.S. Pat. No. 3,898,389, which discloses an electrical interconnect device, the surface of which has been coated with a thin metallic layer.
As the popularity for electrical interconnect sleeves has increased so has the need for low cost interconnect sleeves. Applicants herein have developed a method and an apparatus for use in making a low cost interconnect sleeve having a electrically conductive coating which is tenaciously bonded to the interior surface of same.
In the past there have been many methods and apparatuses for applying conductive coatings to selected areas of articles. For example, J. J. Torok, U.S. Pat. No. 2,953,483 generally discloses a method and apparatus for vapor deposition coating the surface of an article by confining the article within a chamber, vaporizing the coating and electrically charging the coating and spraying the article with the coating on the unmasked portions. Torok uses a hood for application to the surface of the article. Torok relies upon direct contact of the mask with the article to effect his coating.
Another method and apparatus for vapor deposition coatings is found in Deverse et al, U.S. Pat. No. 3,699,917 wherein solder is deposited onto the terminals of semi-conductor wafers by heating and evaporating solder on a single source. The solder is applied by a plurality of wire rings arranged in a plurality of wafer carrying tiers by exposing the evaporant approximately one-sixth (1/6) of each cycle and then cooling the solder by radiation. Trim tabs between the source and dome assure uniform distribution of solder on all wafers, regardless of tier location. Thus, the solder source rotates applying a uniform distribution (coating) of solder to the wafer (article).
Another method for selectively coating articles is found in R. J. Al, U.S. Pat. No. 3,565,644 wherein selected portions of an article are masked and then fusing pulverulent particles to the surface of the article which are applied by a powder coating method. The article is exposed to elevated temperatures for a prolonged period of time to thermally fuse the coating in place. One embodiment, shown in FIG. 3, illustrates coating a pipe fitting with a powder coating. The fittings are connected by tandem by nipples having chamfered ends, flat sheets of cork are cut to size and wrapped around each nipple and secured thereto by means of adhesive or a wire wrapped around each sheet covering the exterior surface of the nipples. The exterior surface of the fittings are coated with pulverulent coating particles after elevating the temperature.
Nakken, U.S. Pat. No. 2,891,880 discloses a vacuum deposition process for producing film resistors. A helical resistance ribbon is applied to the surface of a tubular insulating material by use of a bimetallic helical mask wherein different co-efficients of expansion of the metals are used to hold the mask onto the insulator. It will be noticed that the interior walls are necessarily in contact at all times with the mask. This method of producing resistor rings is particularly dependent upon the precise contact of the tubular article with the mask. In this manner, the coatings applied to the tubular article are the precise thickness required.
Although it has long been known to apply coatings to an article through a vapor deposition process as illustrated by the above, no one heretofore has discovered a method and apparatus for selectively coating the interior surface of tubular interconnect articles. Applicants here, have developed a novel method and apparatus which may be utilized in making cost efficient, selectively coated tubular interconnect articles as set forth above and as will be appreciated more fully hereinafter.